By default, most systems will duplicate to multiple displays when a MST hub is attached. If you are getting mirrored displays and cannot detect more than one display in Screen Resolution or Display Settings, your graphics card may not be compatible with MST. For more information about how to determine if your graphics card is MST compatible, refer to the following FAQ: https://www.startech.com/faq/mst-hubs-gpu-compatibility.
If you are using a version of Mac OSX, refer to the following FAQ for more information: https://www.startech.com/faq/mst-hubs-mac-osx-support.